So Hillary Clinton has finally, and very publicly, got in touch with her emotions. Almost ten years to the day after she reacted more like a thwarted political strategist than a wronged wife to the news of her husband’s affair with Monica Lewinsky, Hillary has come close to tears on the campaign trail in New Hampshire.

Her trademark helmet of blonde hair never flinched, but Mrs Clinton’s face mottled and her eyes momentarily filled as she answered questions about the demands of the presidential primary season.

“It’s not easy,” she faltered, briefly overcome by exhaustion and frustration at being thrown so suddenly and comprehensively on to the back foot by her Democratic rival Barack Obama.

“I have so many opportunities for this country and I just don’t want to see us fall backwards, you know?”

But ironically, in a race that has seen the male candidates for the US presidency shedding tears on a weekly — and in Republican frontrunner Mitt Romney’s case almost daily — basis to show their sympathetic side, Hillary’s moment of vulnerability may well sound the death knell for her struggling campaign.

Far from reassuring the US electorate that ambition has not turned her into an insensitive bitch after all, the thought that she may be far too feminine to hold high office will terrify them.

For men the so-called “political risk of emotion” has been neutralised since Senator Edmund Muskie’s 1972 presidential campaign dissolved after it was reported that he had cried in response to a newspaper attack on his wife — despite his insistence that it had been melted snowflakes, not a tear, in his eye.

But for women it remains strictly off limits. Former congresswoman Pat Schroeder is still getting grief today for crying when she announced she was withdrawing from the presidential race in 1987.

“I got a devastating e-mail about it from a woman writer just a couple of days ago,” Schroeder says. “It’s like I ruined their lives, 20 years ago, with three seconds of catching my breath.”

Professor Tom Lutz, the author of Crying: A Natural and Cultural History of Tears, puts the problem down to tears being a sign of submission. And who wants someone submissive leading foreign policy? Or someone emotionally unstable with the mandate to initiate nuclear war?

But it is not just in politics that crying acts like kryptonite on the prospects of women who want to be taken seriously. From my experience of working on stock exchange trading floors, newsrooms and legal chambers, women who cry instantly reinforce the old stereotype that pressure turns all females into overly hormonal and manipulative wrecks.

They tend to win the specific battle as nobody, least of all a man, can bring themselves to berate a woman in tears. But the damage that these sobbers do to the reputation of working women in general is catastrophic.

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